Hydraulic pressure applying tool



May 10, 1960 N. F. ATHERTQN HYDRAULIC PRESSURE APPLYING TooL May 10,1960 N. F. ATHERTON HYDRAULIC PRESSURE ARRLYING Toor.

2 Sheets-Sheet 2 Filed Aug. 5

INVENTOR.

AT1-o A/Ey.

United States Patent 2,935,851 j HYDRAULC PRESSURE APPLYING rooL NeilVF. Atherton, Bayside, Wis., assignor to Blackhawk Mfg. Co., West Allis,Wis., a corporation of Wiscon- 'sin Application August 5, 1957, SerialNo. 676,220

2 Claims. (Cl. 60-52) This invention relates to hydraulic pressureapplying tools, such as hydraulic jacks, and in particular toimprovements in the release valving therefor, and to the fabrication ofsuch a jack.

Many uses for a jack of this type require a dependable but inexpensiveunit which is expendable. They are expected to perform with somewhat thesame eiciency as other jacks but must be produced in large volume at aminimum of cost to the user.

These jacks must frequently be capable of use in a variety of positionsand must have a release valve which permits the jack to contractquickly. Such a valve should best be operative without the use ofspecial or separate tools which often become mislaid or lost.

In accordance with this invention a jack has been provided whichfulfills the above requirements.

Another object of the invention is to provide a jack which is veryeconomical to manufacture and which utilizes a maximum number of commonparts, consequently requiring minimum toolage, for various sizes ofjacks.

Another object of the invention is to provide a hydraulic jack in whichthe entire pump for supplying pressure to the lifting cylinder may bequickly and easily moved to a fluid releasing position; thus serving asa release valve. A

Other objects and advantages will appear hereinafter as this disclosureprogresses, reference being had to the accompanying drawings in which:

Figure l is an elevational view, in section and with parts broken awayand removed, of a jack made in accordance with this invention, and inthe retracted position with the pump in the pressure deliveringposition.

Figure 2 is a view similar to Figure l but showing the jack as used inthe inverted position.

Figure 3 is an enlarged fragmentary view in elevation o f a portion ofthe jack and showing the pump actuating handle and linkage therefor.

Figure 4 is a fragmentary view, generally similar to Figure 1, but on anenlarged scale and showing the piston in the partially extendedposition.

Figure 5 is a View similar to Figure 4 but showing the pump moved, orbacked off `to thepressure releasing position.

Figure 6 is a plan view of the relationship between the pump and varioussizes of cylinders useable therewith.

Referring more particularly to the drawings, a dishshaped member 10 iswelded around vits periphery to the base plate 11 to form a housing forthe unit land a reservoir for the fluid yl2. The member 10 is stampedfrom sheet steel and has an opening 13 in its upper central portion andanother opening 14 adjacent thereto. These openings 13, 14 are formed bya punching operation holds kthe ram in its load holding position.

Patented May 10, 1960 2 stock, extends through opening 13 and has atransferv plate 19 welded to its lower end as at 20. A valve bodystandard 21 is rigidly secured, as by welding, to the upper side oftransfer plate 19.

The dish-shaped member 10, transfer plate 19, cylinder 18 and valve bodystandard 21 are all secured together to form a unitary assembly. Toassemble this unit, the valve body standard 21 is iirst welded to thetransfer plate 19 and the latter is then welded to cylinder 18. Cylinder18 is then inserted in position in opening 13 and welded therein, as at22, 2.3. The Abase plate 11 may then be positioned over the downwardlylopen recess ofthe member 10 and the peripheral edge thereof is thenwelded to the member 10 as at 24. f

A ram assembly 25 is reciprocatingly mounted within cylinder 18 andincludes a load engaging saddle or pad 26 at its upper end, and a rambearing 28, flexible ram cup 29 and retaining washer 30 secured by nut3.1 at its lowe'i end.

A cap top 34 is press-tted over the upper rend-of cylinder 18 and holds'the flexible ram wiper 35 and the steel ram stop ring 36 securely inplace. An inwardly turned flange of the top 34 aids in guiding the ram.The top cap is press-tit to the cylinder so as to function as a safetyrelief device. If the pressure in the cylinder exceeds a pre-determinedamount, the cap simply is blown of the cylinder. This would, of course,happen only on extremely rare occasions and is a valuable safetyfeature.

A pump body 38 extends through opening 14 and is in sealing relationshiptherewith by means of the sealing ring or packing 39. The body isthreadably engaged as at 49 with the standard 21 and extends downwardlytherethrough. At the lowermost end of the body is a beveled end orprojection 42 which is adapted to seat in the aperture 43 in thetransfer plate 19. A fluid passage in the form of bore 44 extendsthrough plate 19 and places aperture 43 in liuid communication with theinterior of cylinder 18 as at 46'. Thus a conduit is formed between thecylinder and reservoir. A ball 45 is press-tit in the end of bore 44 tothereby seal the same. Ball 47 in bore `44 is located adjacent the valveprojection `42 and permits llow of hydraulic fluid in only onedirection, that is, into the cylinder, when the projection 42 is' seatedin the valve seat formed by aperture 43, as will more fully appearhereinafter. l

A pump plunger 50 is reciprocatingly mounted in the cylinder Slil formedin the valve body and has a ball-like upper end 52. An O-ring seal 53 ina groove in the valve body acts to seal the plunger in the body.

A vertical bore 55 in the valve body connects the cylinder 51 with bore44 of the transfer plate; Ball 47 is adapted to seat against the lowerend of the bore 55 when the bodyl 38 is screwed down into the pumpingposition and the plunger is not delivering fluid to the cylinder 18.Y Inother words, the ball 47 acts to prevent returnv ilow of fluid from thecylinder 18 to the reservoir and A crossbore -57 extends partiallythrough the valve body and has a ball 5S press-fit into its outer end toseal the latter. Ay smaller cross bore 59 connects the b0reh5-'7 withthe lluid in the reservoir. Openings 60 in the standard permit free flowof iluid from the reservoir to bore 59. A ballY 62 in bore 57 permitsfluid liow from-,the reservoir into VerticalV bore 55 but preventsreturnow from bore 5'7 through bore 59 by seating on the shoulder vformed between bores. 57 and 59.

which also forms an annular flange 15, 16, respectively,

therearound. The reservoir is rather at in appearance, like a disk, theplate 11 forming the lower side and portion 10 forming the upper side. Apressure tube in the form of cylinder 18, formed from relatively thintubular The pump unit and the lifting cylinder are thus both mounteddirectly to the transfer plate which contains a `The means for actuatingthe plunger 50 is shown in Figure 3 and includes a link retainer 64secured to the top of member and in which is swivelly mounted the ballend 65 of pump link 66. The upper end of link 66 is also formed as aball 67. An adapter sleeve 68 swivelly receivesvthe ball ends 67 of thelink and 52 of the plunger. The actuating handle 70 to which sleeve 68is attached is moved vertically about ball 67 as a pivot to pump theplunger up and down.

A major portion 72 of the length of the pump body is hexangular in crosssection and over which is adapted to t in mating relationship therelease handle 74. A circular portion 75 is cut from the pump body andwhen the handle is moved to this circular portion it is free to turnwithout turning the pump body. By means of the handle 74 the body isturnable in the housing opening 14 and is thus raised up or down bymeans of its threaded connection to the standard Z1.

As shown in Figure 1, the beveled projection at the lower end of thepump body is seated in the inlet aperture 43 in the transfer plate. Byturning the handle a small abount, on the order of one quarter of aturn, the pump body can be raised to the release position shown inFigure 5.

t When a downward pumping stroke is imparted to the plunger S0, the ball62 seals bore 59 and fluid is forced out opening 43, through bore 44 andinto the cylinder 18 to raise the ram. At the end of the downward strokeof the plunger, the pressure in cylinder 18 and bore 44 acts to seatball 47 in bore 55. On the suction or upward stroke of the plunger; ball62 unseats and uid iS sucked into cylinder 51 through bores 59, 57 and55, thus recharging the pump for the next pumping stroke. The process isrepeated until the ram has been extended the desired amount.

When it is desired to withdraw the ram into cylinder 18, therpump body38 is given a slight turn by means of handle 74 so as to unscrew thethreaded portion 4t! slightly and thus raise the body to the positionshown approximately in Figure 5. By this means a considerable opening 78is quickly made betweenthe beveled projec- Vtionv42 and the opening 43to release the uid in cylinder 18 to the reservoir. The releasearrangement is very simple with no additional levers or valves to getout of adjustment, the pump housing acting as a valve part.

Thus the transfer plate 19 provides a uid passageway from the valve tothe cylinder 18. The plate 19 also serves as a mounting plate forsecuring the cylinder 18, standard 21 and pump body thereto. Such anarrangement results in an economical structure which can readily beassembled.

As shown in Figure 6, various sizes of transfer plates may be useddepending on the size of lifting cylinder. .When a larger jack isrequired, for example one having a larger cylinder 81 as shown by thebroken lines, then a correspondingly larger transfer plate 82 would beused. However, it will be noted that the distance between the aperture43 and the opening 46 in the transfer plate 19 is the same regardless ofthe size cylinder and plate used. By maintaining this distance constant,common toelage,

such as drilling jigs and fixtures, may be used for form-l ing the fluidpassage in the transfer plates. A common size pump unitincluding thestandardZl can be used for any size cylinder desired.A

Attention is directed to the fact that the annular side wall 84 of thehousing 10 is formed on a taper, in other words, the side slops upwardlyand inwardly as shown in Figure l. This construction permits the use ofa smaller reservoir and still insures that the jack will be operative ineither of the positions shown in Figures l and 2.

It will be noted that the inlet 59 for the pump is located below thehorizontal centerline of the height of the reservoir, when the jack isin the position shown in Figure l, and the level of the fluid issuiciently high to insure full extension of the ram 25 without the fluidlevel in the reservoir dropping below the pump inlet 59.

When the jack is inverted to the position shown in Figure 2, the pumpinlet 59 is well above the horizontal centerline of the reservoirheight. In order to be sure the inlet 59 is covered with duid for anyposition of ram extension, the level of fluid must be considerablyhigher in the reservoir when the jack is inverted than when it is in thenormal position of Figure l. This is accomplished by having the upperportion of the reservoir of smaller cross-sectional area, for example,by tapering the sides upwardly and inwardly as shown. This results inbeing able to use a smaller reservoir and consequently one requiringless material to manufacture.

By means of this invention, an expendable tool is provided which iseconomical to manufacture and has a built-in safety feature. A releasemeans is provided for quickly dumping the pressure fluid in the ramcylinder by means of a tool which cannot be forgotten or lost and isalways ready for instant use. The jack is operative in either the normalor inverted position without the necessity of an exceptionally largereservoir.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim:

1. A hydraulic pressure applying tool comprising, a housing formed by abase plate and a cap peripherally secured thereto to define a fluidreservoir, a separate fluid transfer plate seated against said baseplate entirely within said reservoir, a pressure cylinder having one endsecured to said transfer plate, said cylinder extendingoutwardly fromsaid reservoir through said cap and being secured thereto, a hollowthreaded spacer member secured to said transfer plate laterally of saidcylinder, said spacer member being housed entirely within said reservoirand having side wall openings placing the interior thereof lin directcommunication with said reservoir, said transfer plate having apassageway therein communicating with said cylinder and with saidreservoir through the side wall openings of said spacer member, and apump body threadably received by said spacer member within saidreservoir and having one end thereof normally seated against saidtransfer plate to shut off communication between the passageway in saidtransfer plate and said reservoir, said pump body extending outwardlyfrom said reservoir through said cap and having sliding coactiontherewith to permit positive longitudinal movement thereof upon rotationto and from seated fluid delivery position and pressure releasingposition.

2. A hydraulic pressure applying tool comprising, a housing formed by abase plateand a cap peripherally secured thereto to define a uidreservoir, a separate fluid transfer plate seated against said baseplate entirely within said reservoir, a pressure cylinder having one endsecured to said transfer plate, said cylinder extending outwardly fromsaid reservoir through said cap and being secured thereto, a hollowthreaded spacer member secured to said transfer plate laterally of saidcylinder, said spacer member being housed entirely within said reservoirand having side wall openings placing the interior thereof in directcommunication with said reservoir, said transfer plate having apassageway therein communicating with said cylinder and with saidreservoir through the side Wall openings of said spacer member, a pumpbody threadably received by said spacer member within said reservoir andhaving one end thereof normally seated against said transfer plate toshut off communication between the passageway in said transfer plate andsaid reservoir, said -pump body extending outwardly from said reservoirthrough said cap and having sliding coaction therewith to permitpositive longitudinal movement thereof upon rotation to andfrom seatedfluid delivery position and pressure releasing position, and a checkball confined in said References Cited in the tile of this patent UNITEDSTATES PATENTS Sunderman Aug. 29, 1922 8 Stephens July 28, 1936 MuellerJan. 13, 1948 Mueller Ian. 27, 1948 Humphreys Oct. 12, 1948 Mueller Oct.26, 1948 Mueller Feb. 28, 1950 Mueller Apr. 17, 1951 Johansson et al.Apr. 1, 1958

